3 Common Grinder Pump Problems

An unburied grinder pump holding tank.

A grinder pump, or sump pump, is a waste-management device designed to be used with toilets, washing machines, dishwashers, showers, and other devices that produce waste water. The grinder pump turns all of this water-carried waste into a kind of slurry, which is then transported to local sewer systems.

These pumps are often buried underground and can be difficult to access by those who are not professionals. For home improvement enthusiasts who are keen to take on any jobs around the home including the grinder pump, knowing the kinds of problems these pumps face will help them to practice some easy maintenance and perhaps save them the cost of calling out a plumber.

1. Blocking

Grinder pumps can easily be blocked by dirt and debris. Some pumps use a floater device to sense the level in the tank, which triggers the activation of the grinder pump, but this floater can be prone to a buildup of grease and dirt that can sometimes cause the pump to turn on when it is not needed or not turn on at all. The first indication that this might be the problem is if sewage leaks into the house or yard. It is sensible to hose down the grinder pump in order to remove dirt and grease from the floats.

A similar problem can be caused by the careless dumping of waste into the pipes, including kitty litter, oil, paint, and other non-soluble items. These items can collect in the bottom of a holding tank before clumping together with other debris to jam the pump. Even items which are flushable can cause problems to a sump pump, such as disposable napkins, which have become well-known in plumbing circles for forming large wads that block the pump. The simple answer is not to flush anything that seems likely to cause a jam.

2. Clotting

If larger pieces of debris can get stuck in the pump itself, then smaller items can also cause a gradual build-up of silt which also damages the pump. The pump may become slower or may start making a whining noise every time it activates in this case. This silt can eventually build up to the point where it is triggering the pump on a frequent basis as well. If you have this problem, then you may need to call in a plumbing expert to get the silt removed before the pump can be used again.

3. Freezing

The grinder pump is buried underground, and in warmer locations, it is not necessary to place it more than a few feet down. In climates which experience deep frost, however, the sump pump has to be buried below the frost level—the level to which frost reaches into the earth. Common problems include the grinder pump not being buried below this line, and so water waste, or the resulting slurry, becomes frozen and jams the pump. Make sure that you know how deep frost can reach, and take care that your pump is buried deeper. Freezing can damage pipes, so be careful about any plumbing leading to and from the grinder pump as well.